DanG wrote:
I would guess that you have a loose or disconnected neutral
somewhere in that circuit. It could be at any receptacle, switch,
or point of use, or even the panel itself.

The interrupted, usually black, wire that you read on each side
of the switch is the hot. Neutrals are typically white. If your
switch has a black and white on the switch, it is a "switch leg" -
a way to use normal Romex while ignoring color conventions
(pretend both wires are black).

Of course, a good electrician uses tape or a permanent marker to mark
the ends of the white wire, in that application. Just being polite to
the next guy in there 20 years later, who may get distracted before he
puts the wall or ceiling box back together. (especially the ceiling box)

--
aem sends...